Conventionally, when semiconductor devices such as LSI and VLSI and liquid crystal display panels or the like are manufactured, the light is irradiated on photosensitive materials coated on semiconductor wafers or original panels for liquid crystal to form a pattern of photo-resist. In this case, if a dust adheres to a photo-mask used, this dust absorbs and reflects the light. Therefore, the pattern to be transcribed is sometimes deformed and the edge of a photo-resist is sometimes rough. For this reason, size, quality and appearance or the like of obtained products are damaged and the performance and the manufacture yield of semiconductor devices and liquid crystal display panels are decreased, which was a problem.
A patterning operation of the above photo-resist is generally carried out in a clean room. However, it is difficult to keep the photo-mask always clean even inside a clean room. Therefore, a pellicle used for exposure, which transmits the light well, is applied on the surface of the photo-mask so that the dust does not adhere to the photo-mask. Hereby, the dust does not adhere to the surface of the photo-mask directly, but adheres to the pellicle film, which has an advantage where effects of the dust on the pellicle on the patterning can be avoided by bringing the pattern on an original plate for exposure into focus when the light is irradiated.
A pellicle generally consists of a thin pellicle film, a frame made of aluminum, an adhesive agent for fixing the pellicle film to the frame and a tackiness agent for fixing the pellicle to the photo-mask. The above tackiness agent is covered by a separator, which is fixed when the pellicle is shipped, the said separator is taken off when the pellicle is used, and the pellicle is fixed to the mask by pressing the exposed tackiness agent of the pellicle to the photo-mask.
A pellicle, shipped from a pellicle maker in a state of being put in a pellicle case, is taken out from the case by a photo-mask maker and is applied to the photo-mask. A photo-mask for a semiconductor is generally 6 inch square, and a pellicle fixed to it is rectangular, having a long side of about 147-150 mm and a short side of about 110-125 mm (FIG. 1).
The photo-mask maker takes out the pellicle from the case, checks whether it can stand the test and applies it to the mask, then it is confirmed as acceptable. When handling this pellicle, in some cases, a handling operator handles it by hand. Namely, a handling operator opens the pellicle case with gloved hands, grabs the pellicle with gloved hands directly for inspection, then puts acceptable products into a pellicle mounter, and applies the pellicle 1 to the photo-mask 10 using the pellicle mounter (FIG. 1). On this occasion, there was a problem that the pellicle becomes dirty, in a high possibility, with the foreign substances, since the handling operator touches the pellicle directly.
On the other hand, the handling operator sometimes uses a handling tool like one shown by FIG. 2 (Patent document 1) when he handles the pellicle. The arms 5 of both sides of this tool have the insertion pins 7, which work as the holding claws. The said arms 5 open and shut from left to right to grasp or release the pellicle. As for the grasped pellicle, generally, two holes 8 which receive the above insertion pins are provided in an each long side of the pellicle, so that the total 4 holes are provided. The handling tool holds the pellicle by inserting the above insertion pins 7 into these holes 8 (FIG. 3).
In the case of using the aforementioned tool, a handling operator holds only the handle 3 of the handling tool and does not touch the pellicle directly. Therefore, it is prevented that the pellicle becomes dirty because of the indirect handling by the operator. However, in the case of using the aforementioned conventional tool, it is necessary to insert the insertion pins 7 into the above holes 8. If the locations of the insertion pins 7 are not sufficiently accurate, the insertion pins 7 are not inserted into the said holes 8, and the insertion pins 7 would hit and push the pellicle frame 2. This might cause a problem that the frame 2 is distorted inwardly (FIG. 4) and this distortion produces wrinkles on the pellicle film set on the frame 2. Furthermore, in order to solve this problem, it is required that not only the locations of the holes 8 provided in the pellicle frame 2 but also the locations of the insertion pins 7 provided on the tool should be sufficiently accurate. This was another problem since this pushes up the end-product cost.
In addition, the distance between the holes 8 provided in the pellicle frame 2 is generally 104 mm, which is a constant distance. However, the distance of the holes 8 from the bottom face of the frame might be different depending on the pellicle (FIG. 5). Owing to this fact, it is difficult to insert the insertion pins 7 into the respective holes, and the distortion of the pellicle frame 2 occurs frequently. In such cases, it is necessary to prepare several kinds of handling tools to meet the variously positioned holes, which is troublesome.